package com.sen.gulimall.cart.interceptor;

import com.sen.common.constant.AuthServerConstant;
import com.sen.common.constant.CartConstant;
import com.sen.common.vo.MemberRespVo;
import com.sen.gulimall.cart.to.UserInfoTo;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.UUID;

/**
 * @author Kisen
 * @email lqs0911@qq.com
 * @date 2022/11/13 13:23
 * @detail 在执行目标方法之前，判断用户的登录状态。并封装传递给controller目标请求
 */
public class CartInterceptor implements HandlerInterceptor {

    public static ThreadLocal<UserInfoTo> threadLocal = new ThreadLocal<>();

    /**
     * 执行目标方法之前
     *
     * @param request  current HTTP request
     * @param response current HTTP response
     * @param handler  chosen handler to execute, for type and/or instance evaluation
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        UserInfoTo userInfoTo = new UserInfoTo();
        HttpSession session = request.getSession();
        MemberRespVo member = (MemberRespVo) session.getAttribute(AuthServerConstant.LOGIN_USER);
        if (member != null) {
            //用户登录
            userInfoTo.setUserId(member.getId());
        }

        Cookie[] cookies = request.getCookies();
        if (cookies != null && cookies.length > 0) {
            for (Cookie cookie : cookies) {
                //user-key
                if (CartConstant.TEMP_USER_COOKIE_NAME.equals(cookie.getName())) {
                    userInfoTo.setUserKey(cookie.getValue());
                    userInfoTo.setTempUser(true);
                }
            }
        }
        //如果没有临时用户一定分配一个临时用户
        if (StringUtils.isEmpty(userInfoTo.getUserKey())) {
            String uuid = UUID.randomUUID().toString();
            userInfoTo.setUserKey(uuid);
        }

        threadLocal.set(userInfoTo);

        return true;
    }

    /**
     * 目标方法执行之后：分配临时用户，让浏览器保存
     *
     * @param request      current HTTP request
     * @param response     current HTTP response
     * @param handler      the handler (or {@link HandlerMethod}) that started asynchronous
     *                     execution, for type and/or instance examination
     * @param modelAndView the {@code ModelAndView} that the handler returned
     *                     (can also be {@code null})
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

        UserInfoTo userInfoTo = threadLocal.get();
        //如果没有临时用户一定保存一个临时用户
        if (!userInfoTo.isTempUser()) {
            //持续的延长临时用户的过期时间
            Cookie cookie = new Cookie(CartConstant.TEMP_USER_COOKIE_NAME, userInfoTo.getUserKey());
            cookie.setDomain("gulimall.com");
            cookie.setMaxAge(CartConstant.TEMP_USER_COOKIE_TIMEOUT);
            response.addCookie(cookie);
        }
    }
}
